In this file image made from an undated video provided Thursday, June 5, 2014, by Al Fajer, a Sudanese nongovernmental organization, Meriam Ibrahim, sitting next to Martin, her 18-month-old son, holds her newborn baby girl that she gave birth to in jail, as the NGO visits her in a room at a prison in Khartoum, Sudan.

A Sudanese mother sentenced to death for “abandoning” Islam for Christianity walked free from prison Monday after a court overturned her conviction, a rarity in a country that strictly interprets Muslim law.

The case drew global outrage that was amplified because Ms. Ibrahim, whose husband Daniel Wani is an American, was eight months pregnant when convicted. She gave birth to a daughter while shackled in prison.

During her trial prosecutors had argued that because Ibrahim’s father was a Muslim, that automatically made her one, and she had therefore illegally married a Christian. She told the court her father had left the family when she was young and she was raised a Christian by her mother.

US Secretary of State John Kerry had said the US was “deeply concerned” at Mr. Wani's wife’s imprisonment. David Cameron, Britain’s Prime Minister, called it "barbaric."

It is doubtful that such international condemnation influenced the judges sitting at the Court of Appeal in Khartoum, Sudan’s capital, as they considered an appeal lodged by Ibrahim’s lawyers on June 4.

Details of the decision, issued Monday, were few. Sudan’s state news agency SUNA carried a brief statement saying only that the Appeal Court “issued a judgement on release of the prisoner…and dismissing the decree issued earlier."

The ruling followed a plea from an organization called the Commission for the Defense of Women, the statement said.

Illegal marriage

If the judges’ full ruling confirms that it was swayed by arguments over gender equality, that would also be a rarity in Sudan, where women’s rights are limited.

Inter-religious marriages are illegal in Sudan, and Ibrahim was judged to have committed adultery by being with her husband. For that crime, she was to be punished with 100 lashes.